Many people think of carbohydrates as the "white" foods—bread, pasta, potatoes, cake—but the nutrient group includes vegetables, whole grains, legumes (black beans and lentils, for example), and fruit, which are just about the healthiest foods on the planet. "These are healthy carbohydrates," says nutritionist Bonnie Brehm, PhD, an assistant professor at the University of Cincinnati College of Nursing who has studied low-carbohydrate diets, "and they are full of great nutrients: fiber, vitamins, antioxidants." Processed carbs—the cakes, cookies, white bread—are the ones that are more questionable. They generally carry few nutrients and break down quickly in the body.